Assuntos
Linfócitos/efeitos dos fármacos , Rifampina/intoxicação , Trombocitopenia/induzido quimicamente , Trombocitopenia/diagnóstico , Testes de Toxicidade/métodos , Adulto , Anemia Hemolítica/sangue , Anemia Hemolítica/induzido quimicamente , Anemia Hemolítica/diagnóstico , Feminino , Humanos , Imunoglobulina E/sangue , Técnicas In Vitro , Trombocitopenia/sangueRESUMO
Sixty-eight patients underwent dipyridamole thallium imaging and exercise blood pool imaging in order to determine the functional significance of various dipyridamole thallium imaging redistribution patterns. Serial thallium images and blood pool regional wall motion were interpreted by three independent observers. Rest and exercise left ventricular ejection fractions were calculated by two observers and were averaged. Transient thallium defects were associated with normal rest and exercise left ventricular ejection fraction and regional wall motion. Mild persistent thallium defects were associated with normal ejection fraction and regional wall motion at rest, with a deterioration in both with exercise. Severe persistent thallium defects were associated with reduced ejection fraction and regional wall motion at rest, but no further deterioration with exercise. These data support the following postulates: Transient dipyridamole thallium defects are due to mild coronary artery stenoses that cause no detectable functional consequence during levels of exercise achieved in this study. Mild persistent defects are due to more severe stenoses that do cause a functional reduction in wall motion during exercise. Although appearing qualitatively persistent, these defects probably represent very slow thallium redistribution and ischemia rather than scar. Finally, severe persistent defects probably represent myocardial scar.
Assuntos
Dipiridamol , Teste de Esforço , Coração/diagnóstico por imagem , Tálio , Adulto , Idoso , Angiografia , Doença das Coronárias/diagnóstico , Doença das Coronárias/fisiopatologia , Dipiridamol/metabolismo , Eletrocardiografia , Feminino , Hemodinâmica , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Cintilografia , Volume Sistólico , Tálio/metabolismoAssuntos
Catecolaminas/administração & dosagem , Dobutamina/administração & dosagem , Insuficiência Cardíaca/tratamento farmacológico , Digoxina/administração & dosagem , Dopamina/administração & dosagem , Quimioterapia Combinada , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Humanos , Contração Miocárdica/efeitos dos fármacos , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/fisiopatologia , Nitroprussiato/administração & dosagem , Consumo de OxigênioRESUMO
Changes in cardiac performance and coronary hemodynamics were evaluated during dobutamine infusion in patients with chronic heart failure associated with ischemic heart disease. At the maximal administered dose (10 micrograms/kg per min) cardiac index increased by 54 percent and stroke work index by 65 percent, indicating improved left ventricular function. Coronary sinus flow and myocardial oxygen consumption increased concomitantly, but myocardial lactate production occurred in only one of eight patients. These findings suggest that improved left ventricular function with dobutamine is associated with increased myocardial oxygen consumption; however, overt myocardial ischemia occurs infrequently.